Intercultural competence has acquired an important role in the foreign language classroom. However, we must also come to terms with assessing this highly complex construct if we consider it as a superordinate learning objective. Therefore the components of intercultural communicative competence that go beyond knowledge, especially attitudes, deserve closer attention. On the basis of Byram’s (1997) model of Intercultural Communicative Competence (ICC), an attempt has been made to trace the development of attitudes as part of ICC in computer-mediated intercultural communication. Data was drawn from three e-mail projects that took place between 2001 and 2002. Three different upper-secondary classes at a vocational school in Mainz, Germany (n=64) exchanged e-mails with two groups of US-American undergraduate students in Ohio (n=57) and one group of undergraduate students of English from Tokyo (n=30). Preliminary findings from a telecollaborative seminar with US-American undergraduate teacher students at a German teacher training institution were used to support the data. The main question addressed in the paper is whether attitudinal components of ICC can be measured quantitatively in telecollaborative environments. To do this, specifications and implementation of learning objectives for attitudes as put forward by Byram (1997) are applied to different instruments within the framework of the e-mail projects, including a triangulation of instruments. Instruments include e-mails, critical incidents, essays and interaction journals. When data was ambiguous or incomplete, follow-up interviews were conducted with pupils. Results of the study suggest that it is not possible to measure attitudes with the instruments described, but that they can help teachers to describe evidences of attitudes in interaction and trace developments to provide a basis for feedback.